The present invention relates generally to techniques that cause an object or objects to have relative motion. For example, techniques can cause relative motion of objects within a sensing region relative to a sensor or sensing component such that the sensor or sensing component provides sensing results that indicate waveforms with time variation resulting from the relative motion.
U.S. Patent Application Publication No. 2008/0181827 describes techniques that use spatially modulated excitation/emission and relative movement between a particle and an excitation/emission pattern. For example, an interference pattern of excitation light with submicron periodicity perpendicular to particle flow can be used; other types of spatial modulation include a spatially modulated mask or micro-lens or micro-mirror array, electric or magnetic fields, acoustic field, molecular coating creating fluorescence quenching, and micro-cavity. As the particle moves along the pattern, emission is modulated according to the speed of the particle and the periodicity of the stripe pattern; examples of signals that may be used include periodic, chirped, and random signals. A single detector, which records emission over a couple of stripes, can be used. The signal can be recorded with fast detector readout to capture “blinking” of particles while moving through the excitation pattern. More generally, an environment can be provided along a channel that causes a particle to create a time modulated signal that is detected, such as by an optical array or electrode array, and evaluated. A system can also include means for providing relative movement between a particle and a spatially modulated excitation region; relative movement may be created by the particle moving, a detector/optical elements moving along, for example, the channel, or by movement of both. For example, a particle may be conveyed in a fluid, could be on a bio-chip, or could be suspended in a fluid and housed on a slide on the bed of a scanner with modulation patterns that move in substantially perpendicular directions. Techniques for evaluation of signals are described in U.S. Patent Application Publication No. 2008/0183418.
It would be advantageous to have improved techniques for causing objects to have relative motion within sensing regions.